> > what'is the real difference between:shutdown(8),
> > poweroff(8),reboot(8) and halt(8) ?
>
> The shutdown tool is setuid root and only executable
> by root or members of
> the operator group (so runs with root privilege). It
> can be used to set
> when a shutdown should happen. It runs in the
> background, logs about the
> shutdown, and sends shutdown messages to the
> terminals of current logins
> (using wall) warning when the shutdown will happen.
> If the shutdown time
> is within five minutes it creates a /etc/nologin
> file which is honored by
> login, sshd, and a PAM module to prevent new logins.
> Then shutdown runs
> the /etc/rc.shutdown script. Basically that script
> runs the rc.d scripts
> containing the "shutdown" keyword in reverse order
> with the "stop" command
> line argument. And then shutdown runs halt (or
> reboot).
>
>
> The halt, reboot, and poweroff tools are just the
> same command. It will
> log to the wtmp and wtmpx login databases about the
> shutdown or reboot, do
> a sync so pending disk writes are completed, kill
> init, send a SIGTERM to
> all non-kernel processes, waits two seconds, does a
> sync again, waits
> three more seconds, sends an uncatchable SIGKILL to
> all processes (and
> retries that if needed a couple times), and then
> reboots the system or
> halts the processor(s).
>
> Running poweroff will power off the hardware (on
> supported systems).
>
> (I have more details in my NetBSD book in process.)
My goal is to write a software GUI/GNOME for netbsd,
which supports the commands: shutdown,
poweroff,reboot, halt
NetBSD is Very JIHBED, JIHEBD it is word arabic == TOP AND POWER INTELLIGENT
http://jihbedunix.blogspot.com